Rapping plate



T. L. RUDDY RAPPING PLATE Oct. 11, 1949.

Filed March 26, 1946 INVENTOR. Flames 51: R000) I BY' w, Mm, 5 7

H r roe/vs ys Patented Oct. 11, 1949 i UNITED STATES P ATEN T OFFICE 2,484,746 RAPPING PLATE 7 Thomas Lee Buddy, Lakewood, Ohio Application March 26, 1946, Serial No. 657,290

This invention relates to rapping plates for ate tachment to molding patterns and the like, and has for one of its objects the provision of a device of this kind that may be so substantially and firmly secured to the pattern that it will withstand the severe service to which it is ordinarily subjected.

A further object of the invention is to provide a very simple device of this kind which will be inexpensive to manufacture, light in weight, and durable.

Another object is to provide a rapping plate which has an increased surface area to bear against the patternto whichit will be applied and yet which will be light in weight and easy to apply.

A more specific object is to provide ara-pping plate capable of distributing a force applied to it from any direction over a greater area of the pattern, thereby reducing the possibility. of: deformation of the patternandthe .ultimateloosening of the plate.

Another specific object is to provide a new and novel rapping plate so strengthened that warpage resulting from long use will be reduced.

A further specific object is to provide a rapping plate having a new and novel means of preventing loosened hold-down screws from interfering with the makin of perfect patterns.

Other objects of the invention and the features of the novelty will be apparent from the following description taken in connection with the accompanying drawing, wherein like characters indicate like parts, of which Fig. 1 is a top view illustrating my improved rapping plate.

Fig. 2 is a longitudinal section through the rapping plate on the sectional line 2-2 shown as though mounted on a pattern, and

Fig. 3 is a bottom view of my improved rapping plate showing in detail the depending lugs and webbing of the plate designed to engage the pattern.

Referring to the drawing, I indicates generally a pattern such as is commonly made of wood or other material, and 2 indicates the rapping plate which is attached to the pattern by means of the screws 3.

The rapping plate may be made in various sizes and shapes to suit different patterns but as illustrated consists of a substantially hexagonal shaped plate 4 having sides substantially perpendicular to the plane of the plate. Depending from the plate 4 and with their outer surfaces flush with the outer surface of the sides are a plurality or depending lugs 5, B, l and 8. The outer surface 1. Claim. (01. 22- 186) of these lugs, as well as the sides of: the plate, are substantially perpendicular to the plane of the plate 4. The other surfaces of these lugs including longitudinaledges 9, l0 have all been-provided with a slight taper. In use, the full surface of these lugsis in engagement with the pattern and any blows delivered to the rapping plate will be distributedto the pattern throughoutthisarea-of contact. The taper permits a-slight wedging action when the lugs are driven intothe holes. provided for. them so asto increase the firmness of their-bearing on thepattern material.

Also depending from the lower surface of the plate 4 and preferably on the centerline is a boss ll, preferably made hollowasv at l2. inorderto keep the weight of the rapping plate as low as possible. The outer surface of. this boss is also designed to be in firm engagement with the pat.- tern material and aids in, transmitting theforce ofthe blows to the patternv material.

Extending from the boss ll outwardly are ribs [3. These ribs not only serve to give added strength to the boss but also serve to further increase the area of the surfaces in contact with the pattern capable of transmittin the force of the blows to the pattern material. In addition these ribs considerably increase the bending movement of the plate so as to reduce to a minimum warpage from excessive use. Preferably these ribs extend in a direction such that their surfaces will be at an angle with the major surfaces of the depending lugs 5, 6, l and 8. This serves to increase the number of surfaces which will have a plane perpendicular to the direction of any blow delivered to the plate.

Holes I! and 18, having a slight taper, are designed to receive a rapping or withdrawal bar. They are placed outwardly of the center of the rapping plate in order that blows thereon will tend to give a slight turning movement to the plate, which in turn is transmitted to the pattern so as to aid in the patterns removal.

Recesses 20 are provided in the surface of the plate around each hold-down screw hole to permit the screwhead of the hold-down screw to be countersunk well below the surface of the plate. Thus a loosened screw will not interfere with the matching of the opposite halves of the pattern. Malleable lugs H! are provided in the recesses 20 which can be bent over the head of the screws 3 to prevent removal or loosening of the screws.

The location and the design of the lugs 5, 6, l and 8 is such as to make the operation of applying the rapping plate to a pattern and locating the holes for the lugs a simple matter. The plate is laid bottom side up on the pattern and the outline of the plate traced thereon with a pencil.

- As the outer surfaces of the lugs are flush with be easily located by means of the intersection of diagonal lines drawn from the corners of the outline and a drill used to make this hole. Then by means of a routing tool the remainder of the pattern is cut away to a depth egualto that of p I I v disposed substantially centrally of each depresthe plate 4. The plate is then placed in this opening and hammered into place. blows are sufiicient that the webs I3 will deform the-pattern material and make their own space. If not, a space may be cut for them. The screws 3 are then applied and the malleable lugs I9 hammered over to prevent the screws from coming out. s

Thus it is seen that'I have described a rapping plate simple in construction and easily applied which will have a firm engagement with the pattern overa much larger area than has heretofore been known in devices of this kind, which will prevent warpage and-which will prevent loosened screws from interfering with the making of perfect' patterns.

While I have illustrated and described what I now consider to bethe preferred form of my invention, it will be understood that changes in the shape and arrangement of .the parts may be made without departing from the spirit of the invention as defined in the appended claim.

Having thus described'my invention, I claim:

The hammer A rapping plate for patterns or the like coniprising a plate member, a plurality of spaced lugs integral with said member and extending outwardly from one face of the latter with the outer surface of each lug substantially perpendicular to the plane of the member and flush with a portion of theperiphery thereof, the inner surfaces of said lugs being substantially planar and tapering towards said outer surfaces, a hollow boss extending" outwardly "from a central imperforate portion of said one face of the member, a

plurality of webs radiating from said boss and integrally united with the latter and with the said one face of the member, the other face of said member being provided with a plurality of depressions of substantial dimensions with a screw-receiving opening through the member sion,and a plurality of lugs in each depression adjacent the opening therein, the last-mentioned lugs being integral withsaid member and adapted to be bent over the'heads of screws in said openings and depressions to prevent the screws from being displaced outwardly thereof.

' THOMAS LEE RUDDY.

' REFERENCES CITED The following references are'of record in the file of this patent:

PATENTS Ruddy Apr. 29, 1941 

